Avante Integration

Add MCP capabilities to Avante.nvim by following these steps:

Add Tools To Avante

require("avante").setup({
    -- system_prompt as function ensures LLM always has latest MCP server state
    -- This is evaluated for every message, even in existing chats
    system_prompt = function()
        local hub = require("mcphub").get_hub_instance()
        return hub and hub:get_active_servers_prompt() or ""
    end,
    -- Using function prevents requiring mcphub before it's loaded
    custom_tools = function()
        return {
            require("mcphub.extensions.avante").mcp_tool(),
        }
    end,
})

• The get_active_servers_prompt() function adds the running MCP servers from MCP Hub to system_prompt
• The mcp_tool() function adds two custom tools use_mcp_tool and access_mcp_resource to avante.

Configure Avante Integration

By default, MCP server prompts will be available as /mcp:server_name:prompt_name in avante chat.

require("mcphub").setup({
    extensions = {
        avante = {
            make_slash_commands = true, -- make /slash commands from MCP server prompts
        }
    }
})

Tool Conflicts

MCP Hub's built-in Neovim server provides some basic development tools by default.

Avante also provides built-in tools for file operations and terminal access. You need to disable either the MCP Hub's built-in tools or Avante's tools to avoid conflicts. If you prefer to use neovim server tools, you should disable the corresponding Avante tools to prevent duplication:

require("avante").setup({
    disabled_tools = {
        "list_files",    -- Built-in file operations
        "search_files",
        "read_file",
        "create_file",
        "rename_file",
        "delete_file",
        "create_dir",
        "rename_dir",
        "delete_dir",
        "bash",         -- Built-in terminal access
    },
})

Auto-Approval

By default, whenever avante calls use_mcp_tool or access_mcp_resource tool, it shows a confirm dialog with tool name, server name and arguments.

Global Auto-Approval

You can set auto_approve to true to automatically approve all MCP tool calls without user confirmation:

require("mcphub").setup({
    -- This sets vim.g.mcphub_auto_approve to true by default (can also be toggled from the HUB UI with `ga`)
    auto_approve = true, 
})

This also sets vim.g.mcphub_auto_approve variable to true. You can also toggle this option in the MCP Hub UI with ga keymap. You can see the current auto approval status in the Hub UI.

Fine-Grained Auto-Approval

For more control, configure auto-approval per server or per tool in your servers.json:

{
    "mcpServers": {
        "trusted-server": {
            "command": "npx",
            "args": ["trusted-mcp-server"],
            "autoApprove": true  // Auto-approve all tools on this server
        },
        "partially-trusted": {
            "command": "npx", 
            "args": ["some-mcp-server"],
            "autoApprove": ["read_file", "list_files"]  // Only auto-approve specific tools
        }
    }
}

You can also toggle auto-approval from the Hub UI:

• Press a on a server line to toggle auto-approval for all tools on that server
• Press a on an individual tool to toggle auto-approval for just that tool
• Resources are always auto-approved (no configuration needed)

Function-Based Auto-Approval

For maximum control, provide a function that decides approval based on the specific tool call:

require("mcphub").setup({
    auto_approve = function(params)
        -- Auto-approve GitHub issue reading
        if params.server_name == "github" and params.tool_name == "get_issue" then
            return true -- Auto approve
        end
        
        -- Block access to private repos
        if params.arguments.repo == "private" then
            return "You can't access my private repo" -- Error message
        end
        
        -- Auto-approve safe file operations in current project
        if params.tool_name == "read_file" then
            local path = params.arguments.path or ""
            if path:match("^" .. vim.fn.getcwd()) then
                return true -- Auto approve
            end
        end
        
        -- Check if tool is configured for auto-approval in servers.json
        if params.is_auto_approved_in_server then
            return true -- Respect servers.json configuration
        end
        
        return false -- Show confirmation prompt
    end,
})

Parameters available in the function:

• params.server_name - Name of the MCP server
• params.tool_name - Name of the tool being called (nil for resources)
• params.arguments - Table of arguments passed to the tool
• params.action - Either "use_mcp_tool" or "access_mcp_resource"
• params.uri - Resource URI (for resource access)
• params.is_auto_approved_in_server - Boolean indicating if tool is configured for auto-approval in servers.json

Return values:

• true - Auto-approve the call
• false - Show confirmation prompt
• string - Deny with error message
• nil - Show confirmation prompt (same as false)

Auto-Approval Priority

The system checks auto-approval in this order:

1. Function: Custom auto_approve function (if provided)
2. Server-specific: autoApprove field in server config
3. Default: Show confirmation dialog

Usage

1. Start a chat in Avante
2. All the tools, resources, templates from the running MCP servers will be added to system prompt along with use_mcp_tool and access_mcp_resource tools.
3. Avante will call use_mcp_tool and access_mcp_resource tools when necessary